Work-holder for buttonhole-sewing machines.



E. B. ALLEN. WORK HOLDER FOR BUTTONHDLE SEWING MACHINES. APPLICATION FILED APR. 29, I9I2.

1,240,642. Patented sept. '18, 1917,

3 SHEETS-SHEET I.

Q IIAIIIIIIg v v I /I TTORNEY t y E. B. ALLEN.

WORK'HOLDER FOR BUTTONHOLE SEWING MACHINES.

APPLICATION FILED APR. 29, ISI-2. I 1,240,642. y Patentedsepn 18,1917.

3 SHEETS-SHEET 2.

I E. B. ALLEN. WORK' HOLDER FOR BUTTONHOLE SEWING MACHINES. APPLICATION ULED APR. 29. 1912.

1,240,642.- Patentedsept. 18,1917.

3 SHEETS-SHEET 3.

mi www.

Urnrnn santas PATENT clarion.

EDWARD B. ALLEN, 01T' BRIDGEPORT, CONNECTICUT, ASSIGNOR TO TI-IE SINGER MANUFACTURING COMPANY, A CORPORATION 0F NETW JERSEY.

WORK-HOLDER FOR BUTTONI-IOIE-SEWING MACHINES.

Specification of Letters Patent. Patented Sept, '18, 1917.

Application filed April 29, 1912.. Serial No. 693,778.

It fzZ whom t may concern.'

Be it known that I, EDWARD B. ALLEN, a i

citizen oi the United States, residing at Bridgeport, in the county of Fairlield and State or' Connecticut, have invented certain new and useful Improvements in Work- Hclders for Buttonhole-Sewing Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a special construction i'or the. work-holder of a buttonhole sewing' machine and means for operating the same. It has for its objects to provide effective means for opening and closing the clamping members; to maintain the work clamped in the holder for the least possible time requisite for the cutting and stitching operations, so as to insure against .needless loss of time in the shifting and adjusting' otl the work between consecutive stitching operations; to provide means Jfor the relative adjustment of the opposed clamping jaws; to provide means of adjustment for the lift of the upper clamping jaws it'or Jfabrics ot different thicknesses g. to provide simple and effective means for spreading apart the separable pairs of opposed clampinf; jaws, and actuating means therefor; to 'facilitate the removal of one or both of the separable parts ot the work-holder to provide access to the parts of the mechanism beneath the same; and to otherwise improve the. work-holder in its construction and actuating means.

In its preferable embodiment7 the prese-ntA improvement is .applied to a -buttonhole stitching machine of the type represented in my United States Paterituo. 1,024,490,

dated April 30, 1912. The work-holder comrises a travelinoslidelate connected. with P e and deriving operative movement-s from the feeding mechanism and provided at one end with spaced notches in which are confined by means of a pivotally mounted locking lever ulcrumed thereon headed pivotal studs depending from v.two independent clamp-plates resting upon said slide-.plate and drawn together with their adjacent edges in abutting relation by means of springs.

Upon each clamp-plate at .the end opposite its depending stud is secured n for transverse adjustment thereon a bearing bracket upon which is fulcrumed a ytilting block havingsecured thereon for endwise adjustment `a .clamping lever Carrying a foot constituting one of the clamping jaws opposed to a jaw afforded by the clamp-plate. A spring interposed between the clampplate and said clamping lever forces the latter upwardly to retract t-he upper clamping jaw. Vlvlounted upon said bearing bracketis a controlling cam adapted to force said lever down upon the work and provided with a lateral arm having an tending cam-shaped end portion.

A clamp-.closing rock-lever is fulcrumed upon the carrying member of one of the slit-cutting elements with one arm operatively connected with another member carrying the other of the slit-.cutting elements, whilean oppositely extending arm of said rock-lever, in the advance movement of the traveling slit-.cutting device, first engages and depresses the cam-shaped end por.- tion of the controlling-cam lever-arm and subsequently engages the same intermediate its ends for a second andfinal stage of the clamp-.closing action, the second stage oc-` curing as the slit-cutting elements approach each other in a cutting operation,

. The unclamping of the work is eiiiectedv upwardly eX- ently pivoted rclamp-plates is rjourlflaled .a

rotary cam-button having' rigidly connected therewith a lateral arm to which'is applied a. spring for normally maintaining the .cambutton in unspreading position. The engagement of .said lateral armby a reciprocating bar connected with and the traveling support for the slit-cutting mechanism acts to turn the cam-buttoninto spreading position Vwherein it is held by a actuated by spring-pressed latch-lever engaging said lateral arm. The retraction of said latch-lever by engagement of a thread-cutter actuating bar deriving operative movements from a connection with the feeding mechanism permits the cam-button to return to initial unspreading position under the action of its spring.

1n the accompanying drawings, Figure 1 is a side elevation and Fig. 2 a plan of the forward portion of a buttonhole sewing machine below the bracket-arm, and embodying the present invention. Fig. 3 is a bottom plan of the same with the base partially in section. Fig. 4 is a sectional side elevation and Fig. 5 a rear end view of that portion of the machine provided with the step-motion. Fig. 6 is a front elevation, partly in section, showing a portion of the frame7 the slide-plates sustaining the workholder, and the looper mechanism. Fig. 7 is a perspective view of a portion of the work-clamp, and Fig. 8 a similar view of one of the lower clamp-plates. Fig. 9 is an edge view, partly in section, of the work-s holder, and Fig. 10 a perspective view of one of the controlling cams for the clamping f levers. Figs. 11, 12 and 13 are perspective views representing portions of the clampspreading device. y

As represented in the drawings, the frame of the machine is constructed with the hollow rectangular base 1 having a suitably apertured top forming the bed-plate 2 from the rear end of which rises the hollow standard 3 of the bracket-arm. The hase is shown provided with the removable section 4 for access to the looper mechanism at the front.

v Suitably journaled in the base is the longitudinally extending main-shaft 5 formed with quartering cranks 6 embraced by the lower ends of pitman-rods 7 by means of which it is connected with the upper needleactuating shaft.

Journaled in the lower portion of the standard 3 is the transverse cutter-shaft 8 provided upon its front end with a loose grooved belt-wheel 9 adapted to be connected by a belt with the source of power independently of the main-shaft 5. Between the hub 10 of the belt-wheel 9 and the disk 11 iixed upon the shaft S is a clutch device controlled by means of the iange 12 of the controlling lever 13 fulcrumed at14 and pressed normally into clutch-disengaging position by means of the spring 15 interposed between the flangev 12 and the boss 16 of the bed-plate 2.

The cutter mechanism is shown and described more fully in my application Serial No. 593,784, iiled Nov. 23, 1919. It comprises the traveling fulcium-plate 17 having its opposite edges fitted within suitable `guideways 18 of the bed-plate and provided with the spaced upwardly projecting lugs y portion 22X of the lower lever 22 in contact with the lower side of the cylindrical collar 25 fixed upon the cutter-shaft 8, and the lower edge of the upper cutter upon the .periphery of the actuating cam 26 lixed upon the cutter-shaft. The cam 2G is formed to produce upon the upper cutterlever a two-stage operative movement to give the opposed cutting members successively a rapid closing movement and agreatly retarded work-engaging or cutting movement.

The cutter-shaft 8 has fixed thereon the disk 27 formed with a Cain-groove 28 entered the lateral stud 29 of a link 30 having its enlarged rearward end portion 30X yoked to embrace the cutter-shaft 3 and its forward end apertured to receive the studholt 31 projecting laterally from a rearward extension of one of the fulcruin-sustaining lugs 19, whereby the fulcrum-plate and the cutter-levers fulcrumed thereon are given tiaveling movements toward and .from stitching position preparatory and subsequent to each slit-cutting operation.

The top of the bed-plate 2 is formed with lateral guiding grooves 32 entered by inwardly projecting ribs 33 upon the loiigitudinally extending bars 34 connected at their rearward ends by the plate 35 to form the main slide-frame of the work-holder. The hars 34 are provided with depending apertured lugs 36 in which is sustained the transf verse rod 37 having slidingly fitted thereon the apertured lugs 38 depending from the bottom of the cross slide-plate 39 resting upon the bed-plate with its notched rearward edges fitted to the correspondingly notched confining blocks 40 secured upon the member 35 by means of screws 41.

At its forward extremity, the slide-plate 39 is formed with the spaced notches or open-ended slots 42 which are entered bv the shanks 43 of studs having heads 44 and depending from near the forward and inner edges of the swinging'clamp-plates 45 and 46 which are formed in their adjacent edges with the complemental notches 47 forming an elongated aperture embracing the paths of movement of the needle and the upper cutting member, the upper faces of these clamp-plates being roughened at 43 to afford the lower clamping aws. Fulcrunied upon the lower face of the slide-plate 39 by means of the screw-stud 49 is the curved locking lever 50 formed in its rearward edge with spaced notches 5l adapted to embrace the heads el of the studs yi3 to lock them within the notches i2 of the slideplate. The lever 50 has an additional notch 52 entered by the shank of a clamp-screw 53 tapped into vthe slide-plate 39 by means of which the locking lever may be firmly secured in operative position.

Each ofv the clamp-plates is provided at its rearward end with a stud 54 adapted to enter an aperture in a detachable fingerplate 55 to which is connected one end of a spring 56 having its opposite end attached to a stud 57 sustained by the slide-plate 39.

The clamp-plates 45 and 46 are thus normally drawn together to maintain them in operative relation for the cutting andl stitching of a buttonhole, but by disengaging the finger-plate 55 from the stud 54 and removing the spring 56, either slideplate may be swung outwardly upon its pivotal stud 43, as represented in F ig. 2, for access to the lower stitch-forming mechanism,` the slide-plate 39 being out out centrally at 39X to permit such inspection and to provide clearance for the operative parts.

The slide-plate opening 39X is obviously suliicicntly wide to provide easy access to the Vlooper mechanism beneath, and as represented in the drawings has a width somewhat exceeding thatl ot lthe space occupied by the loopers. rlhe top of the slide-plate 39 atiords an unobstructed space adjacent the clamp-plates of such extent as to permit their tree outward movement, as represented in Fig. 2, to substantially uncover theopening 39X, so that the whole of such opening is effective for access to the loopers in threading or adjusting or otherwise manipulating the same. The simple expedient employed for exposing the loop-takers for such purposes greatly facilitates the use of the machine in practical operation.

Each of the clamp-plates 45 and 46 is shown provided in its upper face nea-r the rearward end with a transverse groove 58 entered by the depending tongue 59 of the toot 60 of a bearing bracket formed with a slot 6l to receive the shank of a fastening screw 62 by means of which it is secured for lateral adjustment upon the clampplate. Rising from the foot 60 of the bearing bracket are the spaced parallel for wai'dly extending arms 63 near the bases of which is sustained the transverse fulcrumpin 6a upon which is secured by means of the set-screw 65 the tilting block 66 formed upon its upper tace with the tongue 66X.

Upon the upper face of the block 66 is securedzby means of the screw 67 a spring clamping lever comprising the superposed members 68 and 69, the former of whichis notched near its forward endv to receive the latter so as to afford a clamping jaw in relatively yielding i forward and rearward sections. Both of the lever-members 68 and 69 are formed in their rearward portions with elongated apertures to receive Vthe shanl; of the screw 67, and the member 69 has in its lower tace a groove 69* toreceive the tongue 66X upon the block 66, thereby providing for the longitudinal adjustment of the upper clamping elements.-

Journaled in lugs of the arms 63 is the transverse rock-shaft 70 upon which is lixed intermediate such arms the clamp-lever controlling cam 7l formed upon one side with the cani-rib 72 and upon' the opposite side with the laterally projectingiinger 73. The cam-rib 72`is adapted for engagement with the inclined upper face of a wedgeshaped wear-plate 74 formed. with the slot 75 in its rearward portion t'o embrace the, shank of the screw 67 byr means of which it is adjustably clamped upon the top ot the upper clamp-plate 68, a washer 76 being interposed between the head oi' .the screw 67 and said wear-plate. By adjustingahe position of the wear-plate lengthwise of the clamping lever the clamping pressure of the latter upon the work may be determined and the work-holder may be adjusted tor ditl'erent thicknesses of material. The clamping lever is normally pressed upward, whereby the wear-plate 74 is maintained continuously in operative relation with the cam 7l, by mea-ns of the spring 77 interposed between the bottom of the lower'lever member 69 and the top of the clamp-plate Fixed upon the rearward end of the rockshaft 70 sustained by the clamp-plate a5 is a rearwardly extending cani-arm 78 formed in its rearward portion with the upwardly extending cam-shaped projection 79. Upon the lower cutter-lever 22 is disposed the fulcrum-stud S0 upon which is mounted a clamp-closing rock-lever formed with a rearwardly extending arm 8l having a slot 82 which embraces a screw-stud S3 upon the upper cutter-lever 2l and a forwardly extending arm Se whose depending forward portion 85 is adaptedto engage the. camshaped upper edge or the cam-arm 7S. ln the advance of the slit-cutting mechanism from retracted position7 as representedin Figs. l and 2, to cutting position, the studs 8O and 83 carried by the cutter-levers maiir tain their initial rela-tion, and the rock-lever 8l Si moves bodily forward, thus carryingv ing movement to perform the slit-cutting operation causes the tilting of the rock-lever S1 84 Vand engagement'ot the nose ot the part 85 with that part of the cam-arm 7 8' llO intermediate the part 79 and the supporting rock-shaft, as indicated in Fig. 9, thereby imparting a second stage of turning movement to the rock-shaft and causing the forcible engagement of the cam-rib 72 with the wear-plate 74 to effect the clamping of the work by the clamping` lever.

To insure the closing of the clamping levers in unison, the hub of the cam-arm 78 is formed with an upwardly extending arm 86 formed with a lateral pin 87 adapted to enter the forked upper extremity 88 of an upwardly extending arm 89 fixed upon the clamp-controlling rock-shaft 70 sustained i by the clamp-plate 46. The parts 87 and 88 afford a coupling between the clamp-operating rock-shafts 70 which are readily retracted from operative engagement when the clamp-plates 45 and 46 are separated, as represented in Figs. 1 and 2.

For the manual control of the clamp when desired, the hub 90 of a finger-lever 91 is fixed upon the end of the rock-shaft 70 opposite the cam-arm 78, and this hub is shown formed with a laterally extending lug 92 adapted for engagement with the operative edge of a stopping cam-disk 93 adjustably secured by means of the screw 94 to the forward extremity of the adjacent clamp-bracket arm 63. By suitably adjusting the cam-disk 93 upon the screw 94 as a fulcrum, the degree of lift of the clamplever 68 69 may be adjusted for different classes of work.

The eccentricity of the cam-rib 72 which acts in performing the final clamping` movement is so slight that its engagement with the wear-plate 74 produces no tendency to turn the rock-shaft 70 in the reverse direction to that described, and no other locking means are therefore required to maintain the clamp closed during the stitching operation. The reverse movement of the controlling cam 71 for unclamping the work is effected by the engagement with its lateral finger or arm 73 of a tappet arm 95 secured upon and depending from a reciprocating rod 96 having its forward end journaled in the apertured head 97 of a stud 98 secured in the lower end of the head 99 of the bracket-arm, and having its iattened and apertured rearward end 96e pivotally connected by means of the pin 100 with one end of a link 101 whose opposite end is connected by means of the pin 102 with the upwardly extending arm 103 of an anglelever mounted upon a fulcrum-stud 104 upon the rearward end of the machine base and provided with a rearwardly extending arm 105.

The angle-lever arm 105 rests upon a lug 106 extending laterally from a plungerblock 107 fitted within a cavity therefor in the swinging stop-motion controlling lever 108 which is provided with the boss 109 pivotally mounted by means of the fulcrumpin 110 between the bearing lugs 111 at the rear of the base 1. The plunger-block 107 is normally pressed downwardly by means of the spring 112 interposed between the upper end of a socket therefor in the swinging lever 108 and said block, and has a tooth 107 X adapted to engage the periphery of the stopping cam 113 which in practice carries one of the operative elements of the clutch comprising the disk 114 whose hub 115 is fiXed upon the main-shaft 5 upon which is loosely mounted the belt-wheel 116 formed with a lateral cavity to receivethe clutch-disk 114.

rllhe tilting of the stop-motion lever 108 to laterally withdraw the tooth 107X from the peripheral notch 113X of the cam 113 causes the clutch to establish driving relation between the continuously rotating pulley 116 and the main-shaft through the xed disk 114, and the return of the stopmotion lever 108 to initial position, as represented in Fig. 4, causes the tooth 107X to ride up the eccentric edge of the cam until it snaps into the notch 113X for arrest of the main-shaft. The rise of the block 107 under the action of the stopping cam 113 causes the lifting of the lug 106 whose engagement with the angle-'lever arm 105 causes the rocking of the same and the advance of the tappet-arm in opposition to the spring 117 interposed between the same and the head 97 of the stud 98. In its forward movement, the tappet-arm strikes the arm 73 of the clamp-controlling cam 71 and turns the latter for the release of the clamp. arms which rise under the action of their respective springsL into the position represented in Fig. 1.

The clamp-plates 45 and 46 are provided in their under sides and at their adjacent edges, between the notches 47 and the pivotal studs 43, each with a transverse groove 118 in which is secured by means of screws 119 a hardened lcontact-block 120 for engagement with the rotary cam-button 121 which is shown formed with straight parallel sides and concentrically curved ends adapted to engage the adjacent extremities of the blocks 120. The cam-button 121 is formed at the upper end ofi a rocking pin 122 journaled in the slide-plate 39 and having secured upon its lower end the collar 123 with the oppositely projecting arms 124 and 125. Secured upon the arm 125 is the laterally extending plate 126 having the eye 127 to which is secured one end of a spring 128 whose opposite end is attached to an eye 129 upon the slide-plate 39 and acts to normally maintain the cam-button in what may be termed unspreading position, in which its fiat sides are in contact with the ends of the contact-blocks 120 and the adjacent edges of the clamp-plates 45 and 46 are thus perseries of rack-teeth 136 upon the adjacent edge of the traveling ulcrum-plate 17 of the slit-cutting mechanism. The body of the cam-block 130 has its upper face formed at the outer4 extremity with a bevel, anda lateral extension 130X thereof has the inner extremity of its upper face oppositely bev- `eled for a purpose toy be later described.

The cam-block is normally pressed upwardly against the bottom of the slide-plate 39 by means or' a spring 137 having one arm secured to the block 132 by means of a screw V138 and another arm resting' against the under side of the cam-block, y Y

Journaled upon a stud-screw 139 upon the under face of the slide-plate 39 is a three-armed latch-lever comprising an arm 140 notched in its outer end to form a ldetaining` shoulder 141, a second angularly arranged arm 142 having a lateral linger 143,

vand a third arm l144 in substantial alinement with the arm 142 and provided with an aperture 145 in which is secured one end of a spring 146 whose ,opposite end is connected with the stud 147 upon the slide-plate 39,l The spring 146 serves to yieldingly maintain the latch-lever in normal position with its arm 142 in contact with the stop-pin 148 upon the slide-plate 39. l

1`Vhen the ulcrum-plate 17 advances for a slit-cuttingoperation, the rack-bar 133 retreats and carries with it the cam-block 130 the beveled inner extremity of whose extension 130X rides over the end of the spreaderarm 124, thereby deflecting the camblock from effective engagement with the spreader-arm. In the return of the parts to initial position, the shouldered end of the cam-block extension 130X operatively engages the spreader-arm 124 and thrusts the same forwardly, the arm 125 being thus shifted so as to temporarily deflect the latchlever arm 140 until its extremity passes the shoulder 141, when the latch-lever under the action of its spring 146 snaps into latching engagement with the arm 125, thereby holding the same and the connected cam-button 121 in clamp-spreading position, as represented in Fig. 2 and in dotted lines in Fig. 11, in which the parts are maintained during the whole of the succeeding stitching operation.

As represented herein, the stitch-forming mechanism comprises a laterally jogging needle 149 mounted in the swinging carrier 150 sustained for rotation in the bracketarm head 99. Cooperating with the needle beneath the work-holder are the threaded looper 151 and thenon-.threaded looper 152 and-overlying loop-spreader 153, these looptaking implements being mountedA upon the oscillating carrier 154 sustained by a rotary support, and adapted to coperate with the needle respectively in its .depth-stitch and edge-stitch thrusts, as set forth in detail in my United States Patent No. 1,030,046, dated June 18, 1912. 1n performingits operative movements, the needle descends through the aperture 155 of the needlethroat 156 which is in practice sustained upon a rockin-g yoke and adapted to be temporarily ,displaced from normal operative positionby the advance-of the lower cutting member for a cutting operation.

Secured upon the bottom of the bed-plate 2 by means of screws 157 is aplate 158 carrying a screw-stud 159 upon the top of which mounted the shank 160 vof a thread-trimming knife whose blade 161 has a pathv of movement upon the vfulcium-stud 159 in a plane between the advance or loop-holding position of the non-threaded looper 152 and spreader 153 and the needle-throat 156, as represented in Fig. 6. The knife-shank 160 is provided. with an elongated aperture 162 entered by the head of a screw-pin 163 upon theunder side of an endwise movable bar V164 journaled in a suitable guideway in the top of the bed-plate and having at its rearward end an upwardly projecting hollow post 165 carrying an apertured lug 166 in which is secured one end of a spring 167 screw-stud 169 the roller-stud 170 which is maintained by means of the spring 167 in operative engagement with the pear-shaped controlling cam 171 whose hub 172 is secured by means-of the set-screw 173 upon the upright shaft 174 journaled in suitable bearings of the bed-plate and carrying upon its lower' end the gear-wheel 175 meshing with the gear-wheel 176 secured upon the hub 177 of the rotary feed-wheel 178.

By the described connection, the trimmeractuating cam 171 is caused to rotate in unison with the feed-wheel 17 8. As the greater portion of its periphery is concentric with its axis of rotation, the knife remains stationary during the greater part of the stitching operation, but at the completion of such operation, the eccentric portion engages the rollerstud 170 and thrusts the bar 164 forwardly, thereby causing the blade 161 to pass between the needle-throat-156 and the looper after which the bar 164 is retracted by its spring-167 into initial position and the knifeblade 161 reassumes its retracted position as represented in Fig. 2.

In the advance of the bar 164 for actuation of the trimming knife, its advance extremity 164X encounters the arm 144 of the latchlever by means of which it is shifted into the dotted line position of Fig. 3, thereby releasing the arm 125 of the spreading device and permitting the cam-button 121 to assume initial unspreading position whereby the separable pairs of clamping aws are drawn together by their respective springs.

T he cam 179 on the main-shaft has a groove 180 entered by the roller-stud 181 of the lever 182 fulcrumed upon the fixed stud 183 and having a link connection 184 with the clutch-lever 185 journaled concentrically with the feed-wheel and having its hub 186 provided with notches entered by the inner ends of the clutch-dogs 187 slotted to embrace the depending flange 17 8X of the feedcam, the clutchdogs being maintained yieldingly in operative relation with said fiange by means of the arms 188 secured to the hub 186 normally resting against the springs 189 secured to the adjacent edges of the clutch-dogs. By the means just described, the feed-cam derives a step-by-step partial rotation from the main-shaft during the operation of the stitch-forming mechanism.

The cam-wheel 178 is formed in its upper face with the usual feeding cam-groove 190 and side-shift cam-groove 191. The eamgroove 190 is entered by a roller-stud 192 depending from a lever 193 swinging upon the fixed fulcrum 193 depending from the bed-plate and provided with an upwardly projecting stud 194 entering and engaging the walls of a transverse slot 195 of the work-holder frame-plate 35, whereby longitudinal traveling movements are impart-ed to the work-holder. The cam-groove 191 is entered by a stud 190 depending from the arm 197 of a rock-lever mounted upon the fixed fulerum 198 and having at its opposite end the roller-stud 199 enteringla longitudinal guideway in the block 200 secured upon the under side of the cross slide-plate 39, by means of which lateral shifting movements are imparted to the work-holder for the stitching of the opposite sides and the ends of the buttonhole.

During the travel of the slide-plate 39 in the stitching of abuttonhole, the spreader parts are locked in the dotted line positions represented in Figs. 3 and 11. To prevent the rengagement of the spreader-arm 124 by the cam-block 130, the extremity of the finger 143 of the latch-lever arm 142 is so positioned as to engage the forward beveled extremity of the body of the cam-block, thereby thrusting it aside in the advance of slide-plate 39 and the spreader parts carried thereby, so as to leave the spreader parts undisturbed until the tripping of the latchlever by the thread-cutting action as before described. Y

As described in my Patent No. 1,024,490 before mentioned, the arrest of the mainshaft and the consequent interruption of the operative movement of the clutch-dogs 187 causes the assumption of operative relation between the auxiliary feed-pawl`201 and the segmental series of peripheral ratchet-teeth 202 upon the feed cam-wheel 178 by means of which the rotation vof the cam-wheel is completed at an increased speed, and the operative portion of the trimming knife actuating cam 171 is brought into engagement with the roller-stud 17 O for actuation of the trimming knife 161.

By effecting the closing of the work-clamp in two stages as described, the upper clamping feet are first brought down close to the work to enable the operator to accurately gage the position of the buttonhole relative to the clamping members for a final adjustment preparatory to the actual clamping operation wliich occurs almost simultaneously with but slightly in advance of the actual buttonhole cutting operation.' The closing of the clamp during the slit-cutting operation and opening of the same by a connection with the stop-motion at the instant of arrest of the stitch-forming mechanism affords the operator the longest possible period of time for shifting of the work between consecutive cutting and stitching operations, thereby permitting the machine to be run practically continuously in the production of a series of buttonholes in the same article.

The actuation of the clamp-spreader by a connection with the slit-cutting mechanismk and-early in the retracted movement of .the latter also effects a saving of time, in placing the work-holder in readiness for the stitching operation before the `slit-cutting mechanism returns to initial retracted position after a slit-cutting operation, as it permits the suitable adjustment of the camplate 203 upon the disk 27 to effect an early engagement with the roller 204 carried by the forwardly extending arm 205 of the clutch-lever rock-shaft 110 to set the mainshaft in motion.

Vhile the present improvement is herein shown and described in what is considered its preferable construction and arrangement of parts, it will be readily seen that it is susceptible of very considerable modification in the form andassociation of its various elements, and that the invention is not therefore limited to the specific embodiment herein disclosed.

Having thus set forth the nature of th invention, what I claim herein is 1. In a buttonhole sewing machine, the combination i with a shaft, stitch-forming mechanismvderivingf operative movements uments, andi a work-holder having upper andL lower clamping members separable to re-Y therefrom7 i a stop-motion xcomprisingi a cam plunger `controlled thereby,' and v a work- 5` Aholderl constructed with' clamping members separable to release and clamp the` work `and a controlling'rock-shaft therefor; provided with an arm, of clamp-opening `means Acomjprising a rod carrying a tappet-arm adapted i for engagement"with` the clamp' rock-shaft arm, and an rangle-lever 'for communicating endwisemovements to' the Atappet-arm f carrying -rod from :said plunger.

2.. In a buttonhole i sewing machine,E the i combination 1 with -fstitchLforming mechanism'7 slit-cutting mechanism, a "rotary shaft fromk which the stitch-'forming mechanismfderives operative movements, a stop- :zmotion for-controlling the operation osaid shaft, and a worl-holder` having upper Eand Hlower clamping' members separable-'to release and clamp thewoi.l,"of clamp-'closing 1and `clamp-opening nieans,ffone offwhich is operatively connected with' the 'slit-cutting 'mechanism andthe other-of which is operv atively connected with :said stopmotion- 43. In a buttonho'le sewingfmaehine, lthe f -combination with stitch-forming mechanism, slit-cutting mechanism l i including a cuttercarrying lever andfprovided `rwith means hfor. confining' it permanently to one -iside' of the stitch-formingl mechanism, and

ai=traveling work-holdenh'alvingupper and I Vlowerclamping members separable to rei `lease 'and clamp'thewvorley and a-controlhng vrock-'shaft for saidvworl-holder mounted'to r partake'ofthe travelinglmovements of the same and provided with 1an 'arm,' of :cla-mp- `closmg 'meansactingupon said arm of the l0'-clamplcontrolling rock-'shaft and' operatively connected with and operated'by said cutter-.carrying lever to effect the inal closingfof the-workeh'older substantially simultaneously` With the slit-cuttingaction.

.4.; In albuttonholefsewing'fmachine, the

combination 4with slit-cutting mechanism including a traveling-carriersustaining separablecutting elementsfand a work-holder lhaving: upper 'and lower clamping members -separable toI release -andclamp 'the work,

and a lcontrolling rock-shaft therefor-provided witlr an arm',I 'of vclamp-'closing means Voperativelyconnectedi tofand p'artaking of Vthemovements of ahmember'carrying'one ofsaid*-cutting'e'lements land acting successively upon said armvofthe clamp-controllingrockesh'aft to'parti'ally close fthe clamp lease'and 'clamp the vwork and a controlling rock-shaft therefor provided `with an arm,

oi clamp-closing meansacting upon said arm of `the clamp-controllingl roclsshaft `lland having a positive connectionwith and actuated by said rock-lever.

6.2'In a buttonhole sewing' machine, the combination with slit-cutting mechanism including coperating cutting elements anda rock-lever Acarrying one of said cutting elcments, and a work-holder having upper and lower clamping'members separable to release and clamp the work 'and a controlling rock#shaft therefor provided with an arm,

of aclamp-closing rock-lever mountedy independently of but connected with the cut- `ter rock-lever and adapted for engagement `with the arm of said clamp-controlling 'f rock-shaft.

J 7.' In abuttonhole 4sewing machine, the

lcombination with slit-cutting mechanism in'- cludiug two cutting elements and sustaining members therefor, one 0i which is mounted to perform rocking movements relative to the other7` and a work-holder having upper 'fand l'owerlclamping members separable to release and clamp the work land a ycontrolgagem'entwith said arm of the clainp-controlling rock-shaft.

S. `In a buttonliole sewing machine,V the combination with slit-cutting mechanisminveluding a traveling `'fulcrum-carrier sustain-v ing. a :fulcrum-pin' upon which arev mounted two cutter members `one of which performs rocking movements relative to the other,.and

a work-holder having upper and lower `clamping members separable to release and clamp the work and controlling rock-shaft therefor provided with an arm, of a clampclosing` rock-leverfulcrumedr upon one of the cutter-members and having an; operative connection with the other ofvsaid cutter ment ybers 'and adapted for engagementwith said. arm of theclamp-controlling rock-shaft.

i ,9i Infa buttonhole sewing fmachine, the

`combination with stitch-forming, feeding meansconnected withvand actuated bjf said kfeeding mechanism.

10. In a buttonholeV sewingmachine; the combina-tiony with a Work-holder comprising sepa ra ble pairs of separableV Aclamping j aws, and slit-cutting mechanism comprising cooperating cutting elements mounted upon a CJD Cil

traveling carrier, of clamp-closing means connected with and actuated by said cutting mechanism for closing the clamping jaws of each pair upon the work preparatory to the cooperativo action of said cutting elements upon the work, and means connected with the cutting` mechanism independently of said clamp-closing means for spreading apart said pairs' of lamping jaws subsequent to said cutting action.

11. 1n a buttonhole sewing machine, the combination with stitch-'forming mechanism, slit-cutting mechanism comprising a traveling carrier and cooperating cutting elements sustained thereby with means for impartin to-and-fro traveling movements to said carrier and cuttingY movements to the cutting elements, feeding mechanism, and a worlrholder constructed with separable pairs of clamping aws, of spreading means, an operative connection between said carrier and the spreading means whereby the latter is actuated to separate said pairs of clamping jaws, and unspreading means connected with and deriving operative movements from said feeding mechanism.

1Q. ln a buttonhole sewing machine, the combin ation with stitch-forming mechanism, a work-holder constructed with separable pairs of clamping jaws, and thrcad-cutting` mechanism including a cutting blade operating beneath the work-holder, of clamp-jaw spreading means, and unspreading means actuated by said thread-cutting mechanism and adapted to cause the approach of said pairs of clamping jaws toward each other substantially simultaneously with the severing of the thread.

1n a buttonhole sewing machine, the combination with stitch-forming and slitcutting mechanisms, a work-holder constructed with separable pairs of clamping` jaws, and thread-cutting mechanism including a cutting blade operating beneath the work-holder, of clamp-j aw spreading means connected with and actuated by the slit-cutting mechanism, and unspreading means actuated by said thread-cutting mechanism.

1s. 1n a buttonhole sewing machine, the

combination with a work-holder constructed with laterally7 separable pairs of opposed clamping members connected for lateral movement in unison, of spreading` means including a rotary controlling member whereby said pairs of clamping members may be separated and drawn together, and actuating means for imparting operative movements to said rotary controlling member.

15. Ina buttonhole sewing machine, the combination with a work-holder constructed with laterally separable pairs of opposed upper and lower clamping members, of a rotary cam-button interposed between and in engagement with the lower clamping members, means for turning said cam-button in opposite directions to effect the spreading and unspreading of the clamping members, and means for yieldingly maintaining said lower clamping` members in operative relation with the cam-button.

16. 1n a buttonhole sewing machine, the combination with a work-holder constructed with edgewise separable clamp-plates,clamp ing levers pivotally mounted thereon and carrying clamp-jaws cooperating with said clamp-plates in gripping the work, yieldingly acting means for forcing said clampplates together, and a traveling` slide-plate upon which said clamp-plates are mounted, of a rotary cam-button journaled in said slide-plate between and in operative relation with said clamp-plates and adapted to control their spacingapart, and means for turning said cam-buttoni 17. 1n a. buttonhole sewing machine, the combination with a work-holder constructed with edgewise separable clamp-plates, and clamping levers mounted thereon, of a rotary controlling member for forcing said clamp-plates apart, a lateral arm connected with said controlling member, and means applied to said arm for turning it in opposite directions in spreading and unspreading the work-holder.

18. 1n a buttonhole sewing machine, thel combination .with a work-holder constructed with edgewise separable clamp-plates, clamping levers mounted thereon, and yieldingly acting means for forcing said clamp-plates together, of a rotary cam-button for forcing said clamp-plates apart, a lateral arm connected with said cam-button, and means applied to said arm for turning it in opposite directions in spreading and unspreading the work-holder.

19. 1n a buttonhole sewing machine, the combination with a work-holder constructed with edgewise separable clamp-plates, yand clamping levers mounted thereon, of a rotary cam-button for forcing said clampplates apart, spring-actuated means for yieldingly maintaining said cam-button in one extreme position, means acting in opposition to said spring for shifting said cambutton into the other extreme position, a latch device for maintaining said cam-button in the last-named position, and means for tripping said latch device to permit the button to return to its first-named position.

20. 1n a buttonhole sewing machine, the combination with stitch-forming, feeding and slit-cutting mechanisms, and a workholder constructed with edgewise separable clamp-plates, clamping levers mounted thereon, and yieldingly acting means for forcing said clamp-plates together, of a rotary cam-button interposed between lthe adjacent edges of said clamp-plates and adapted to force them apart, a lateral arm rigidly connected with said cam-button, a spring connected with said arm for maintaining the cam-button in unspreading position, a reciprocating' bar connected with the 'slit-cutting mechanism and acting upon said lateral arm to shift the cam-button into spreading position, a spring-pressed latch applied to said arm for locking the cam-button in spreading position, and a reciprocating bar connected with said feeding mechanism and acting upon said latch to disengage the same from said arm to permit the cam-button to assume unspreading position under the action of its spring.

21. ln a buttonhole sewing machine, a work-holder comprising a clamp-plate, a bearing bracket, means for securing said bracket for transverse adjustment upon the clamp-plate, a tilting block fulcrumed upon said bearing bracket, a clamping lever, and means for securing said clamping lever upon the tilting block adj'ustably in a direction transverse to that of said bearing bracket.

22. In a buttonhole sewing machine, a work-holder comprising a clamp-plate, a

nclamping lever mounted thereon, a controlling cam for said clamping lever, a lateral stop member `rigidly connected with said controlling cam, and an adjustable ystop ladapted for engagement with said stopping member to determine throughvsaid ycam the initial elevated position of said lever.

23. In a buttonhole sewing machine, the combination with stitch-'forming mechanism including` a reciprocating needle-bar ycarrying a needle and coperating loop-taking means, and -a support disposed in a plane intermediate said needle-bar and thel loop-taking means and formed with an 'opening above and affording access to said loop-taking means of a work-holder comprising edgewise separable clamp-plates mounted `above said opening and normally closing the same and pivotally mounted for independent edgewi-se movement at points near their 'adjacent edges, and means whereby said clampplates are normally drawn ytogether while permitting them to b'e separated to expose a substantial portion of said opening for access to 'the looper mechanism.

24.-. In a buttonhole sewing machine, the combination with stitch-forming mechanism including a needle -and coperating loop-'taking means, of' 'a work-holder" comprising laterally separable clamp-plates, a traveling slide-plate disposed above 'said loop-taking means and formed with an Vopening for access thereto, said kslide-plate afford'- ing a support for said clamp-plates -normally covering` said opening and presenting `an unobstructed bearing therefor adjacent th'e outer edges of the same to permit the separation thereof a distance commensurate with the width of the space occupied, by the looper mechanism, and detachable means for yicldingly drawing said clamp-plates toward each other.

25.111 a buttonhole sewing machine, the combination with stitch-forming and feeding mechanisms, of a traveling slide-,plate connected with said feeding mechanism, and a work-holder comprising clamp-plates each having a clamping lever ,mounted thereon and secured uponsaid slide-plate for movement toward and from each other by means of independent pivotal connections includ-ing retractable locking` means adapted to permit the detachment of said clamp-plates from the slide-plate. y

26. In a buttonhole sewing machine, the combination with stitch-forming and feeding mechanisms, of a traveling slide-plate connected with Isaid feeding mechanism, and a work-holder comp-rising clamp-plates each having a clamping lever mounted thereon andvsecured upon said slide-plate by independent detachabl'e pin-and-slot connections.

27. In buttonhole sewing machine, the` combination with stitch-forming and feed` ing mechanisms, of a traveling slide-plate connected with said feeding meghanism and provided at one end with spaced notches and with 1a lpiv-otally mounted locking lever, and a work-holder 4vcomprising clamp-plates each having a clamping lever mounted thereon and a depending headed stud adapted to enter its respective notch in the slide-plate wherein -it is conned by said locking` lever.

Q8. In a buttonhole sewing machine, a work-holder comprising edgewise separable clamp-plates, clamping levers mounted upon said clamp-plates, controlling cams for said clamping levers, lateral arms rigidly connected with Asaid l controlling cams and formed with detachable interlocking connections, and means applied to one of said cams whereby both of said clamping levers are operated.v

29. In a buttonhole sewing machine, a work-.holder comprising edgewise separable clamp-plates, clamping levers mounted upon said clamp-plates, controlling cams for said clamping levers, a lateral arm rigidly connected with one of said cams yand formed with la linger substantially parallel with the aXis of lmotion of said clamping lever, a lateral arm rigidly connected with the other lof said cams and formed with a fork normally 'embracing said finger, and means applied to lone of said cams whereby both of said clamping levers areoperated.

30. In a buttonhole sewing machine, the combination with stitch-forming` and feedien-'g mechanisms, of a traveling slide-plate connected with said feeding mechanism, ed'gewise separable `clamp-plates mounted upon and sustained by said slide-plate and pivotally connected therewith at one end, bearing brackets secured in said clampplates at their opposite ends, clamping levers pivotally mounted in said brackets, controlling cams mounted in said brackets and adapted to operate said clamping` levers, lateral arms rigidly connected with said cams and detachably connected together for movement in unison, and means applied to one of said cams whereby both clamping levers are simultaneously operated.

31. In a buttonhole sewing machine, the combination with a work-holder constructed with laterally separable pairs of opposed upper and lower clamping members, clampopening and -closing means, and a buttonhole cutting device, of means independent of said clamp-opening and -closing means and operatively connected with said cutting device to receive operative movements derived from the lateral movements of the cutting device relatively to said work-holder, whereby said pairs of clamping members may be separated to spread the work.

32. A buttonhole sewing machine, having, in combination, stitch-forming mechanism and a non-rotary work-holding clamp, mechanism for actuating the stitch-forming mechanism and relatively moving the stitchorming mechanism and the work-holding clamp to sew about a buttonhole, an independently actuated cutter, and connections between the cutter and clamp for closing the clamp by movement of the cutter toward the face of the work.

33. A buttonhole sewing machine, having, in combination, stitch-forming mechanism and a work-holding clamp, mechanism for actuating the stitch-forming mechanism and relatively moving it and the work-holding clamp to sew about a buttonhole, a cutter, a cutter-carrying lever, mechanism actuating the lever to move the cutter toward and from the material, and connections between said lever and clamp for closing the clamp by movement of the lever toward the material.

34. A buttonhole sewing machine having, in combination, stitch-forming mechanism and a work-holding clamp, mechanism for actuating the stitch-forming mechanism and relatively moving it and the work-holding clamp to sew about a buttonhole, a cutter comprising cooperating cutting elements, a lever carrying one of said cutting elements, mechanism for actuating the lever to move said cutting element toward and from the material, and means for establishing operative connection between said lever and the work-clamp whereby the latter is closed upon the material.

35. A buttonhole sewing machine, having, in combination, stitch-forming mechanism, a work-holding clamp, mechanism for actuating the stitch-forming mechanism and relatively moving the stitch-forming mechanism and the work-holding clamp to sew about a buttonhole, a cutter, connections between the cutter and Vclamp for closing the clamp by the cutting movement of the cutter, and means timed in its action by a connection with a moving member of the machine for automatically opening the clamp after the completion of the sewing.

36. A buttonhole sewing machine having, in combination, stitch-forming mechanism and a work-holding clamp, mechanism for actuating the stitch-forming mechanism and relatively moving the stitch-forming mechanism and the work-holding clamp to sew about a buttonhole, a cutting device permanently positioned at one and the same side of the stitch-forming mechanism and mounted independently of the work-holding clamp and actuated independently 'of the stitchforming mechanism, and connections between the cutting device and the clamp for closing the clamp by movement of the cutter toward the face of the work.

37. In a buttonhole sewing machine, the

combination with a work-holder having upd per and lower clamping members separable to admit the work, and slit-cutting mechanism comprising a cutting element and a carrier upon which the same is mounted, of anoperative connection between said carrier and the work-holder and controlled by the carrier whereby the work-holder is closed in the movement of the cutting element toward the plane of the operative faces of said clamping members.

38. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder having upper and lower clamping members separable to admit the work, a controlling rock-shaft therefor provided with an arm, slit-cutting mechanism comprising a cutter-carrying member movable laterally toward and from the stitch-forming mechanism in performing an operative cycle, and means connected with said arm of the clamp-controlling rock-shaft and operatively connected with and operated by said member of the cutting mechanism to effect the final closing of the work-holder substantially simultaneously with the slit-cutting action.

v 39. In a buttonhole sewing machine, in combination, a work-holder having upper and lower clamping members separable to admit the work, a controlling rock-shaft therefor provided with an arm, slit-cutting mechanism comprising a cutting element, a pivotally mounted carrier therefor, and actuating means or said carrier and means independent of said actuating means for establishing operative connection between said arm of the clamp-controlling rock-shaft and said carrier for effecting the nal closing of the work-holder substantially simultaneously with the slit-cutting action.

40. In a buttonhole sewing machine, in combination, a Work-holder having upper` and low r clamping members separable to admit the work, a controlling rock-shaft therefor provided with an arm, slit-cutting mechanism comprising a cutting element, a carrier therefor, a fulcrum for said carrier mounted substantially parallel with said controlling rocl-shaft, actuating means for said carrier, and means independent of said actuating means for establishing operative connection between said arm of the clamp-con trolling rock-shaft and said carrier for electing the iinal closing of the work-holder substantially simultaneously with the slitcutting action.

4:1. In a buttonhole sewing machine, in combination, stitch-forming mechanism, a work-holder having upper and lower clamping members separable to admit the work, a controlling rook-shaft therefor provided with an arm, slit-cutting mechanism comprising a reciprocating carrier, a cutting element mounted thereon and movable toward and from the stitch-forming mechanism and said clamping members, actuating means for said carrier, and means independent of said actuating means for establishing operative connection'between said, arm of the clampcontrolling rock-shaft and said carrier for effecting the nal closing of the work-holder substantially simultaneously with the slit-l cutting action.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses.

.EDVARD B. ALLEN.

I/Vitnesses:

STANLEY N. SMITH, E. L. TOLLES.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. G.

Correction in Letters PatentNol 1,240,642

It is hereby certified that in Letters Patent No. 1,240,642, granted September 18,

1917, upon the application of Edward B. Allen, of Bridgeport, Connecticut, for an all @ITO 1' l, improvement in Work-Holders lor Buttonhole-Sewmg Machines,l

appears in the printed Specification requiring correction as follows: Page 10, line 109, claim 35. strike out the Word laterally; and that the said Letters Patent should be read with this correction therein that the same may conform to the g record of the case in the Patent Office.

Signed and Sealed this 20th day of November, A. D., 1917.

[SEA 1..] R. F. VVHITEHEAD,

Acting Commissioner of Pate/n.155'. j Cl. 112ML 

